Method of waste treatment

ABSTRACT

A method of waste treatment in which materials of widely different physical characteristics such as glass, metal, and fibrous and plastic waste are received in a vessel having a rotor rotatably mounted therein, the rotor being adapted to fracture brittle material, compact malleable material, and otherwise pulverize the frangible waste to a particulate form small enough to be extracted through a perforated plate. The rotor also circulates the material in a slurry form within the vessel in a vortical pattern so that the waste is repeatedly treated until it is ejected from the vessel. A series of spaced attrition bars are mounted outwardly of the rotor to provide an annularly shaped, discontinuous attrition surface, and hammers or flails are pivotally mounted on the rotor to reduce into smaller pieces materials which are flung upon or between the attrition bars by the rotor. Where the waste material contains a high proportion of rags, tubing and other stringy material, a rotating chopper blade is provided to chop this portion of the waste into smaller pieces which are more readily handled by the rotor and flails. Waste materials which are not readily reduced to a pulverized state are segregated from those which are and removed separately.

United States Patent [72] Inventors Earl T. Blakley 3,073,535 1/1963Vokes ,1 4. 241/4611 Cincinnati, Ohio; 3,339,851 9/1967 Felton 24l/46.l7

npka, i gzlf a Rapids, Primary Exammer- Donald G. Kelly wk; G Mani,"ammo", Ohio; AnomeyMarechal, Biebel, French & Bugg Peter Seilert.Middletown, Ohio E NO. 1969 ABSTRACT: A method of waste treatment inwhich materials [45] Patented July 27 of widely different physicalcharacteristics such as glass, [73] Assign mesh, Claw"m Company metal,and fibrous and plastic waste are received in a vessel "ammo" Ohiohaving a rotor 'rotatably mounted therein, the rotor being adapted tofracture brittle material, compact malleable material, and otherwisepulverize the frangible waste to a par- [54] METHODOF WASTE TRE TM NTticulate form small enough to be extracted through a per- Claims, 16Drawing Figs. forated plate. The rotor also circulates the material in aslurry 241/21 form within the vessel in a vertical pattern so that thewaste is [52] CL 08 241/88 repeatedly treated until it is ejected fromthe vessel. A series H l l3 16 of spaced attrition bars are mountedoutwardly of the rotor to [51] lnt.Cl .1 B02 18/]2 1, provide anannularly Shaped discontinuous amnion Surface, 241/31 24 and hammers orflails are pivotally mounted on the rotor to [501 Field Search 86 reduceinto smaller pieces materials which are flung upon or between theattrition bars by the rotor. Where the waste material contains a highproportion of rags, tubing and other [56] References Cited stringymaterial a rotating chopper blade is provided to chop UNITED STATESPATENTS this portion of the waste into smaller pieces which are more2,756,646 7/1956 Jones 241/4617 readily handled by the rotor and fl i|waste materials which 2, 9/1958 Holler H 241/46-11 are not readilyreduced to a pulverized state are segregated 2,954,173 9/1960 Dunwody241/24 f tho whi h are and removed separately.

12 A X 64 6] 2 J DRIVE METHOD OF WASTE TREATMENT CROSS-REFERENCE TORELATED APPLICATIONS Application Ser. No.-7l9,l97, filed Apr. 5, I968,for METHOD AND APPARATUS FOR THE TREATMENT OF GARBAGE AND OTHER WASTESby Joseph Baxter, Jr., and now abandoned.

BACKGROUND OF THE INVENTION Municipal wastes will typically includematerials of widely v varying physical characteristics. These mayinclude fibrous materials, such as paper, cardboard and rags, plasticmaterials,

glass, wire, light gauge metallic containers, and relatively heavy,infrangible materials such as heavy metal pipes and iron castings. It isgenerally desirable to separate the relatively infrangible materialsfrom those which may be readily broken down to a small particle size,reduce the latter in an aqueous medium and pump the resulting slurry tofurther treatment stages.

This has conventionally required sorting the waste material prior toreducing the frangible fraction to a size capable of being suspended inan aqueous medium. Additionally, even though the relatively infrangibleportion of the waste is removed, the disparate characteristics of theremaining fraction render them not readily amenable to reduction in asingle treatment. This is particularly true where the waste materialscontain a relatively high proportion of stringy materials, such as rags,tubing, and the like, as is usually found in waste materials receivedfrom hospitals.

It has, therefore, been long recognized that it would be highlydesirable to combine in one treatment the functions of separating therelatively frangible and infrangible portions of the waste material andat the same time efficiently reducing the frangible portion to aparticulate state, even though the physical characteristics of thefrangible portion are quite dissimilar.

SUMMARY OF THE INVENTION The present invention combines, in one system,a series of elements which cooperate both to segregate the frangible andinfrangible portions of the waste material being treated and topulverize the frangible portion to a particle size which permits thewaste to be readily suspended in an aqueous medium for pumping tofurther treatment stations.

Thus in the method of the present invention a rotor mounted in a vesselsets up destructive hydraulic shear forces in the vessel when the vesselis loaded with waste materials and a liquid suspending medium. The rotorcan be of the disc type but may advantageously be constructed inaccordance with the teachings of the US. Pat. to Vokes, No. 3,073,535.With this type of rotor a plurality of arms are provided which enhancethe formation of a vortical flow pattern in the vessel whichcontinuously causes the material to be driven outwardly and upwardlyalong the sides of the vessel to an overhanging wall of the vessel andthen downwardly back into the path of the rotor arms. A perforatedextraction plate may be positioned beneath the rotor so that as thewaste is reduced to the desired size, the action of the rotor forcesthis portion of the material in slurry form through the extraction plateinto a chamber, where means is provided for conveying the slurry awayfrom further treatment.

An annularly shaped, discontinuous attrition surface is formed by aplurality of spaced attrition bars positioned outwardly of the rotor andengaged by swinging hammers or flails mounted on the rotor. Theseelements cooperate with the rotor in reducing waste material to thedesired size and are particularly effective in reducing tubing, rags andthe like. Thus, as tubing, for example, influenced by the vortical flowpattern set up by the rotor, passes between the spaced attrition bars,the rotating flails sever the tubing into shorter lengths.

The outer surfaces of the attrition bars extend substantially verticallyfrom the bottom of the treatment vessel and provide an annular pocketinto which the currents set up by the rotor deposit the relativelyheavier, infrangible portions of the material, thereby segregating thisportion from that which may be more readily pulverized.

Additionally, where the material contains a high proportion of stringymaterials such as tubing and rags, a rotary chopper blade may be mountedin the vessel and positioned so as to receive materials being circulatedthrough the tank by the rotor arms and to chop these materials to a sizemore readily handled by the rotor, attrition surface and flails, andextraction plate.

Thus the present invention provides a method in which, through thecooperation of a series of elements, the relatively frangible andinfrangible portions of the material being treated are segregated andthe frangible portions subjected to a pulverizing action, despite thewidely different physical characteristics of the frangible portion,whereby the pulverized frangible portions are transformed into ahomogenous slurry which can be readily pumped, transported, dewateredand otherwise treated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view, partlyin cross section, of apparatus of the present invention;

FIG. 2 is a plan view with portions broken away for clarity;

FIGS. 3 and 4 are cross-sectional views taken on lines 33 and 4-4,respectively, of FIG. 9;

FIG. 5 is an enlarged cross-sectional view of a portion of the apparatusof the present invention showing structure adjacent the rotor of thesystem;

' FIG. 6 is a plan view of a portion of one of the flails and thediscontinuous attrition surface;

FIG. 7 is a view of a portion of the chopper blade;

FIG/8 is a view of a portion of the bottom of the rotor and an attachedflail;

FIG. 9 is a plan view of a portion of the top of the rotor andassociated elements;

FIG. 10 is a cross-sectional view of a portion of apparatus according toa modified form of the invention;

FIG. 11 is a perspective view of a portion of the attrition plate ofFIG. 10;

FIGS. 12-14 are somewhat schematic representations showing the variouspositions the chopper blade may assume according to the principles ofthe present invention;

FIG. 15 is an elevational view showing a further embodiment of thepresent invention; and

FIG. 16 is a somewhat schematic representation of a complete wastetreatment system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As seen in FIG. 1 of thedrawings, apparatus for practicing the present invention may incorporatea vessel 10 having a bottom wall portion 11 and an upstanding,substantially cylindrical sidewall 12. A continuation 13 of the sidewallextends inwardly and downwardly and terminates in an overhanging lip 14.A ring 15 is positioned between the sidewall 12 and lip 14 with itsoppositely projecting flanges I6 and 17 secured thereto to provide anannular space 18, which may be filled with concrete or the like tostabilize the unit against vibrations imposed by the moving parts of theequipment. Extending downwardly from the right-hand side of the vesselas seen in FIG. 1 is a conduit 19 which permits ejection from the systemofa portion of the waste as described below.

Mounted in the bottom wall of the vessel 10 is a rotor 20 havingoutwardly projecting arms 21 and rotating in the direction indicated bythe arrow in FIG. 2. The rotor 20 may be splined to a shaft 22 mountedin a bearing 23 and extending downwardly into operative association withdrive means 24. Each of the arms 21, as best seen in FIG. 3, has atruncated air foil shape with a substantially flat leading edge 25 whichis slightly inclined from the vertical in a direction downwardly andaway from the direction of rotation of the arms 21. The upper and lowersurfaces 26 and 27 of each arm 21 converge towards each other with thelower surface 27 being curved upwardly away from the bottom of thevessel. The leading edge of each arm 21 may be provided with aprotective strip 28 ofa hardened material such as tungsten carbide orthe like, and a deflecting strip 29 of substantially rectangular crosssection may be attached to the undersurface of the rotor, as moreclearly shown in FIGS. 8 and 9.

The portion of the bottom wall 11 immediately beneath the rotor may beformed as a plate 30 having a series of perforations 31 therein tofunction as an extraction plate. Affixed to the upper surface of theplate 30, as by welding or the like, is a series of substantiallyrectangularly cross sectioned deflecting bars 32 mounted in oppositionto the similarly cross sectioned rotor deflecting bars 29. It will benoted from FIG. 9 that each of the bars 29 and 32 extends at an angle tothe radii of the rotor but in opposite directions, for a purpose to bepresently explained. Immediately beneath the extractor plate 30, asupport plate 33 is secured to provide, with plates 34 and 35, asubstantially toroidal-shaped chamber 36 having an opening 37 thereinattached to a conduit 38. Plate 33 is, of course, provided with openings39 therethrough to permit communication between the vessel interior andthe chamber 36 through the perforations 31.

At least a pair of oppositely extending arms 21 are modified as seen inFIGS. 2, 4 and 9 by providing a cutaway portion 40 having an opening 41therethrough to receive a bolt 43. A flail 44 of substantially L-shapehas a complementary cutaway portion 45 formed on its inner end with anaperture 46 therethrough for receiving the bolt'43. The bolt 43 may bepositioned with an enlarged shoulder 42, and a washer 47 is positionedbetween the opposing portions of the arm 21 and flail 44. Alternativelyof course, the shoulder 42 may be replaced by a bushing. The purpose ofthe shoulder 42, or a corresponding bushing, and the washer 47 is topermit even wear of the more readily replaceable flails, bolts andwashers. The outer end of each flail 44 has an upwardly and outwardlybeveled surface 48, as best seen in FIGS. 4 and 8.

Positioned outwardly of the rotor 20 are a series of attrition barmembers 50 of generally trapezoidal configuration separated by passages56. The bars 50, as best seen in FIG. 2, are conveniently mounted inunits on segment plates 57, which may be secured to the support plate 33by means of bolts or the like 58 (See also FIG. 4). The trapezoidalconfiguration of the bars 50 provides, in addition to the upper andlower parallel sides 51 and 52, a pair of nonparallel sides 53 and 54,each of which serves an important function in the apparatus of thepresent invention.

The substantially vertically oriented surface 53 of each of the barsforms a pocket 55 in the lower portion of the vessel 10 for a purpose tobe presently explained and the surfaces 54 of the bars 50, which arecomplementary to the surface 48 of the flail 44, collectively define anannularly shaped discontinuous attrition surface. While a pair ofoppositely positioned flails 44 have been described for purposes ofillustration, it will be apparent that the number of flails utilized maybe varied as desired, the only limitation being the avoidance of anunduly unbalanced system.

A chopper blade is shown in FIG. 1 as mounted in the sidewall 12 of thevessel 10 on a shaft 61 which extends through the sidewall and isshrouded at 62 and attached to a source of power 64 mounted outwardly ofthe vessel 10. As best seen in FIG. 7, the chopper blade 60 may be ofsawtoothed construction with the teeth 65 of the blade inclined awayfrom the direction of rotation of the blade.

The apparatus thus far described may be operated on either a continuousor a batch basis. However, it will generally be preferable to operate ona continuous basis, and the description of the operation is thereforedirected to a continuous process, although it will be apparent that ithas facility in a batch process as well.

In operation, waster material is delivered to the vessel 10 togetherwith a charge of liquid, which may initially be fresh water but which,as will be explained below, may quite advantageously be raw sewage froma municipal sewage system. The consistency of the mixture in the vessel10 will vary depending upon the amount of glass, metal and the like inthe vessel. Thus, if there is a high percentage of these materials, theconsistency may be as high as 10 percent. However, the consistency ofthe slurry passing through the plate will preferably be approximately 2to 6 percent solids, and the total amount of material will usually bekept rather low to provide a more efficient reducing and segregatingoperation.

The rotor 20, which may operate at a peripheral speed of approximatelyl,000 to 6,000 feet per minute, establishes a vortical circulation pathin the vessel, as indicated by the arrows 70, which subjects thematerial in the vessel to severe hydraulic shear forces. In this regardit should be noted that the horsepower to volume ratio is preferablymaintained relatively high to insure a vigorous flow pattern, with thevolume of material treated ranging from 1.5 to 7.5 cubic feet per unitof horsepower expended. This serves to break up a portion of the wastematerial to smaller sizes and appears to be particularly effective inreducing fibrous materials such as paper, cardboard and the like.

In addition to the attrition caused by hydraulic shear, the arms 21 alsoexert a mechanical destructive force on the waste. Thus the leading edgeof the arm 21, protected by the hardened strip of material 28, definesan impacting surface which extends nonparallel to the plane of rotationof rotor 20 and batters the objects it encounters as it sweeps about thebottom of the vessel, serving to compact light gauge metallic containerssuch as aluminum and tin cans and fracturing relatively brittlematerials such as glass into small particles.

The inclined leading edge of each of the arms 21 also tends to directthe waste material downwardly towards the extractor plate 30, where, ifit is of sufficiently small size, it passes through the apertures 31 andthence, into the toroidal chamber 36 from which it may be evacuated bythe conduit 38. Material which is forced down toward the plate 30 but istoo large to pass through the apertures 31 is sucked upwardly from thesurface of the extractor plate by the negative pressure exerted by thepassage of the upwardly curved surface 27 of each of the arms 21, andthis upward and downward pulsation provides an additional comminutingaction. The deflector bars 29 and 32 cross each other in scissorsfashion and serve to cut and otherwise sweep out any oversize grittyparticles which tend to become lodged between the surfaces of the rotorand the extractor plate 31.

Stringy material, such as rags and tubings, will be flung outwardly bythe rotor toward the attrition bars 50. The space between these barswill preferably be dimensioned to be greater than the diameter of thetypes of tubings and the like which are likely to be encountered so thatthe majority of such tubing may pass between the bars. Therefore, as thetubing passes between the bars 50 it will be severed into shorterlengths by the outer end of the flails 44, which are impelled outwardlyby centrifugal force and engage the annularly shaped discontinuousattrition surface defined by the inclined surfaces 54 of the bars 50.

Because of their pivotal mounting, if a piece of hard waste material isencountered by a flail, it will move away from the direction of movementof the rotor, in the manner indicated by the arrow in FIG. 9, and damageto the flail prevented. Preferably, the outer ends 48 of the flails 44are dimensioned to be wider than the space 56 between adjacent bars 50to prevent the flails from being jammed between adjacent bars anddamaged. Additionally, the spaces 56 between adjacent attrition barstaper outwardly, as best seen in FIGS. 2, 6 and 9, to prevent materialfrom becoming lodged between them, and the bars are angularly orientedwith respect to the radii 59 of the rotor so as to be aligned with theoutward flow created by the rbtor 21) and indicated at 59' in FIG. 6.

As noted previously, the consistency of waste material-in the vessel isdeliberately kept at a level which allows the material to circulate inthe vertical pattern indicated by the arrows 70. Thus, it is redirecteddownwardly back into the rotor and associated flails, thereby repeatedlysubjecting the material to an extremely severe treatment. In this regardthe overhanging lip 14 prevents material from being flung from thevessel when the amount of material in the vessel necessitates it.I-Ieavier,'relatively infrangible waste suchas heavy gauge steel or castiron, is also flung outwardly by the rotor where it tends to follow thegeneral direction of the arrows 70. However, because of its greaterweight, it will only travel a short distance up the bottom wall of thevessel and will then fall downwardly, where it migrates to the generalvicinity of the pocket 55 formed by the vertical surfaces 53 of theattrition bar members 50. Continued circulation and accumulation of thisrelatively heavy infrangible material continues until the naturalcirculation within the vessel causes this portion to be ejected from thevessel 10 through the conduit 19. Thus rather than the relativelyinfrangible portion of the waste being retained in the system, where itwould not only subject the system to excessive wear but would alsooccupy volume which could be best utilized by the more frangibleportions of the waste, it is instead segregated and delivered out of thesystem at an early stage.

While the system as thus far described operates efficiently insegregating the relatively frangible and infrangible portions of thewaste and in pulverizing the frangible portion to a particulate size, incertain instances where the waste contains a high portion of stringy orropy materials such as tubing and rags, additional means may be providedfor breaking down this stringy material to a size more readily handledby the rotor and associated flails.

Thus as seen in FIGS. 1 and 2, the rotating, saw-toothed, chopper blade60 rotating at a peripheral speed of 4,000 12,000 feet per minute may bemounted in the sidewall of the vessel 10 in the path of the materialflung outwardly and upwardly by the rotor whereby any stringy or'ropyportions are chopped into shorter lengths which are more convenientlyhandled by the rotor 20 and flails attrition bars. In practice it hasbeen found that if a chopper blade is not used in situations in whichthe proportion of stringy material is high, this material may wind intoan increasingly larger ball and greatly inhibits the effectiveness ofthe operation.

Turning now to FIGS. 10 and 11 of the drawings, a second embodiment ofapparatus for practicing the present invention will be described. Theembodiment of FIGS. 10 and 11, as in the case of the embodiment of FIG.1, incorporates a rotor 20 in which certain arms thereof are modifiedfor the attachment of flails 44' thereto. However, unlike the previousembodiment, the bottom wall portion 80 beneath the rotor 20 is, with theexception of the opening 81 accommodating the conduit 82, relativelyimperforate. Additionally, the annular attrition surface is formed as anannular plate 83 having spaced ribs 84 formed thereon and a series ofpassages 85 extending through a portion of the plate 83 into the chamber90.

The chamber 90 is coextensive with the apertured portion of the plate 83and is formed by the cover plate 91, substantially vertically extendingwalls 92 and 93 and a bottom wall 94, with egress from the chamber beingprovided by the conduit 95. Thus rather than the particulate materialproduced by the system being directed downwardly through an extractionplate, as in the embodiment of FIG. 1, it is ejected outwardly throughthe openings 85 in the apertured portion of the plate 83 and thence intothe chamber 90, where it is drained by the conduit 95. The conduit 82may be connected to a source of fluid under pressure which may be eitherintennittently or continuously delivered to the space 96 between thebottom of the rotor and the plate 80 and thereby assist in preventing anaccumulation of material in this area.

In the embodiment shown in FIG. 1 of the drawings, the axis of rotationof the chopper blade 60 is normal to the axis of rotation of the rotor20 and on a line which would intersect a line running through the axisof rotation of the rotor. It will be noted from FIGS. 12, 13 and 14 ofthe drawings, however, that it is within the scope of the presentinvention to provide alternate mountings for the blade 60. Thus as seenin FIG. 12, the axis of rotation of the chopper blade 60a may beangularly disposed with respect to the axis of the rotor 20.Alternatively, as seen in FIG. 13, the axis of rotation of the chopperblades 60b is parallel to that of the rotor. FIG. 14 shows yet anotherembodiment wherein, although axis of rotation of the chopper blade 600is again normal to that of the rotor, it is offset with respect thereto.While in all of the embodiments shown only a single chopper blade isutilized, it will be apparent that multiple chopper can also be used toadvantage, particularly in large installations.

In FIG. 15 a further embodiment of apparatus for practicing the presentinvention is shown wherein a rotor 20a is provided mounted in thesidewall of the vessel 10a. In this position the rotor is removed fromthe heavier materials which tend to collect at the bottom of the vessel.While the rotor 20a is shown as associated with an extraction plate 30a,it will be appreciated that the rotor may instead be associated withconstruction of the type shown in FIG, 10. Additionally, a second rotor20b could also be provided with its axis extending normal to the axis ofrotor 20a.

FIG. 16 of the drawings somewhat schematically represents a completesystem in which the apparatus described above may be utilized inpracticing the method of the present invention. Thus a trash segregatingand disintegrating unit, including a vessel 10, may be associated with ajunk catcher 100 by means of a conduit 19 and continuously charged withwaste material by means of the conveyor 101. Liquid, preferably water,may be fed to the vessel 10 by means of a line 102 connected to the junkcatcher 100 and in communication with the vessel 10 via the conduit 19.The slurry of pulverized waster material and liquid passes'from thevessel 10 by means of the conduit 103 and is pumped by means of the pump104 to a separator 105, which mayconveniently be of the cyclone type andwhich serves to separate gritty materials from the slurry. Grit thusseparated from the slurry of waste material may be ejected through theline 106 and collected for disposal by land fill methods or utilized asan aggregate in low load-bearing structures. The remaining slurry ofwaste material may then be conveyed by means of the line 107 to a sewerline 108. Since the grit has been removed in the cyclone there is nodanger of it settling out in and clogging the sewer.

Altemately, the accepts from the cyclone may be passed through a line109 to a thickener 110, which may conveniently be of the screw type.Liquid expressed at the thickener 110 may then be conveyed back to thejunk catcher by means of line 111 in place of or in supplement to theliquid from the conduit 102. The relatively high consistency materialdelivered by the thickener 110 may then be passed through the line 112to a conventional incinerator, an incinerator of the fluidized bed type,or otherwise disposed of.

It is also possible to use the method of the present invention where thewaste material is treated in more than a single communicating operation.Thus the openings through which the pulverized material in the vessel 10are expressed into the line 103 may be relatively large, for example, onthe order of 12-1 1% inches, with the waste material consequentlyreceiving only a fairly coarse treatment. This coarsely divided wastematerial may then bi: conveyed to the cyclone separator 105 to removethe grit fraction of the waste, and the accepts from the separatordelivered through a line 113 to a second apparatus 114 which may be, butnot necessarily is, of the same type as apparatus 10. and which hasopenings therefrom on a much smaller order of magnitude, for example,three-eighths of an inch, than the apparatus upstream thereof. The wastematerial passing from this apparatus may then be treated as describedabove. A system which incorporates a multiple stage comminuting processhas the advantage of a higher throughput rate, since the retention timein each stage need not be as long, and reduced equipment wear,particularly in the stages downstream of the separating apparatus.

From the above, it will be apparent that the present invention providesa method which permits, in a single continuous operation, thesegregation of the relatively frangible and infrangible portions ofwaste material, and the reduction of the frangible portion to a desiredparticulate size, despite widely varying physical characteristics of thewaste. While the method herein described constitutes a preferredembodiment of the invention it is to be understood that the invention isnot limited to this precise method and that changes may be made withoutdeparting from the scope of the invention.

What I claim is:

1. A method of treating heterogeneous waste material comprising:

a. depositing said waste material and a liquid in a treating vessel,

b. establishing a vortical flow pattern of said waste material and saidliquid in said vessel,

c. continuously circulating said waste material and said liquid in saidvortical flow pattern outwardly from the center of said vessel through adiscontinuous attrition surface, upwardly and inwardly of said vessel,and downwardly back toward said center,

d. shearing portions of said waste material as they move outwardlythrough said discontinuous attrition surface by said discontinuousattrition surface and means yieldably cooperating therewith,

e. subjecting said waste material to further comminuting action as itcontinues to circulate in said vortical flow pattern,

. continuously subjecting said waste material to said shear ing andcomminuting action as it is circulated in said vortical flow patternuntil relatively frangible portions thereof have been reduced to atleast a predetermine particulate size, and 1 g. continuously extractingfrom said vessel waste material comminuted to at least saidpredetermined particulate size with a portion of said liquid in slurryform.

The method of claim 1 including:

segregating relatively infrangible portions of said materials fromrelatively frangible portions thereof while said relatively frangibleportions are comminuted, and

. removing said relatively infrangible portions from said vessel.

. The method of claim 1 including:

subjecting, a stringy portion of said materials to a chopping action assaid stringy portion moves upwardly in said vortical flow pattern.

4. The method of claim 1 including:

a. separating gritty materials in said slurry from the remainder of saidslurry, and

b. depositing said slurry in a sewer.

5. The method of claim 1 including:

a. separating gritty materials in said slurry from the remainder of saidslurry, and

b. reducing said remainder of said slurry to a further comminutingaction.

UNITED STATES PATENT GFFICE- CERllFlCZ-l'fh Oi LQREELCMON Patent No. 9Dated July 27, 1971 Earl T. Blakley, David E. Chupka, Donald L. Harbron,Jr. Inventor(s) Paul G. Marsh and Peter Seifert It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 6 (o posite line "10), cancel "and now abandoned" andinsert --now patent No. 3, 549, O92--.

Column 3, line 33, ositioned" should be -provided Column 6, line 13,"chopper" should be --choppers--.

Column 7, line 6, "While" should begin a new paragraph.

Column 8, line'23, following "1" insert --further--.

Signed and sealed this 25th day of Ap il 1972.

' (SEAL) Attest:

EDWARD MELETCIERJR. ROBERT GOTTSCHALK Attesting Officer (Tommissioner ofPatents

2. The method of claim 1 including: a. segregating relativelyinfrangible portions of said materials from relatively frangibleportions thereof while said relatively frangible portions arecomminuted, and b. removing said relatively infrangible portions fromsaid vessel.
 3. The method of claim 1 including: a. subjecting a stringyportion of said materials to a chopping action as said stringy portionmoves upwardly in said vortical flow pattern.
 4. The method of claim 1including: a. separating gritty materials in said slurry from theremainder of said slurry, and b. depositing said slurry in a sewer. 5.The method of claim 1 including: a. separating gritty materials in saidslurry from the remainder of said slurry, and b. reducing said remainderof said slurry to a further comminuting action.